Mrs Blair is understood to have paid for the two-storey property for Miss Blair, who until recently studied European law in Strasbourg, where she had a scholarship. She previously studied at the Sorbonne in Paris.
It follows the purchase of a £1.3m Grade II-listed townhouse for Euan and a £1.13m 'lad's pad' for Nicky.

A source close to Mr Blair said: 'It started once they bought a flat for Euan, and after that it was only fair that all the children got a helping hand on to the property ladder.

'Most parents would draw the line at spending so much – it's not far off £3.5m in total – but the Blairs aren't most parents.' Miss Blair's maisonette boasts three bedrooms, two bathrooms, a living room, dining room and kitchen. A lift connects the flat to a ground-floor garage.

A team of workmen have been renovating and redecorating the property since the Blairs bought it at the end of July. They have installed a bespoke designer kitchen and a new bathroom and replaced carpets with stripped wooden floors.

Mrs Blair and her daughter secured the maisonette for a sum £20,000 below its £995,000 asking price.

A neighbour, who asked not to be named, said of the previous owners, company director Kestin Hare and his wife Gemma: 'They did not know about the involvement of the Blairs until the sale was completed.

'The house had been on the market for three to four months, but the sale went through very quickly. It went through on July 20 and the builders moved in the next day.

'It has been very noisy and I hope it is over sooner rather than later. The work has happened very quickly, so presumably she will be moving in soon.'

Since leaving Downing Street in 2007, Mr Blair is estimated to have made £25m from lectures and lucrative consultancy deals. He can command up to £170,000 a speech and his memoirs, A Journey, are expected to make about £5m for the Royal British Legion.